So, I have this model I'm working on. I'm trying to create normal maps using Maya and Zbrush. I get this texture seam gap after I create the NM in Zbrush. I looked around on the forum and it seems to be a vertex normal issue? How would I go about fixing them?
I played around with the uvmap adjustments in Zbrush but it doesn't really fix the problem. I also tried reuvmapping in maya and transfering the uv details into zbrush with no luck.
Replies
I'm a bit curious what the highest subdivision level and UVs look like. If these are auto-UVs I'd either try playing with the UV smoothing options when baking the map, or clone the result over to the Texture Map subpalette and hit the Fix Seam button to add some more padding.
You could try using UV Master in zbrush to create a new set as well that should be less disconnected. When you say ReUV'ing in Maya had no luck, did you encounter an error when trying to import those UVs or do you mean the new UVs didn't change the result any?
Well It's going to be low poly when finished. I'm not really familiar with rendering low poly in maya unless you mean by high quality preview, everyone is using marmoset render ingame which I don't have access to, so I was just going to create displacement maps and render it in Zbrush.
The piece is pretty basic, like a neck guard thing lol.
Doesn't the Uv Map Boarder only work on zbrush generated maps?
I hand uv all my stuff in maya, I checked the face normals and vertex normals and they "look" fine. I actually tried numerous times trying to copy and paste the uv information from a new cage with really bad results.
I did get some weird results when importing a new cage from maya to zbrush when I hit freeze subdivision levels to get the new uv info. The uv info usually doesn't transfer or moves to one side of the geo.
face/vertex normals in maya.
UV Master -> Maya - > Back to Zbrush?
If you're happy with the UV Master layout, once you send it to Maya there would be no need to send them back to zbrush. Just keep the model as-is in both programs at that point, and flip any textures you bake.
As for the original layout, looking at that last image the appearance of the polyframe makes it look like the UVs aren't merged/healed together. This is something that could probably be checked and fixed quite easily in Maya if it was the case. You could also check in zbrush by going to Polygroups: Auto Groups with UV
If you wanted, you could also upload the OBJ somewhere so we can look at it.
Freezing shouldn't be necessary. As long as you dont change the vertex order, then you'd just have to import the new OBJ and it should update the UVs automatically. It would be worth noting that zbrush flips the UVs so it wont appear exactly the same as you might be expecting, but as long as it doesn't butcher the actual islands themselves then everything should be fine.
UV Master -> Maya - > Back to Zbrush?
- Yes.
As for the original layout, looking at that last image the appearance of the polyframe makes it look like the UVs aren't merged/healed together.
-It's a solid merged object.
If you wanted, you could also upload the OBJ somewhere so we can look at it.
- Sure, where can I upload it to?
Freezing shouldn't be necessary. As long as you dont change the vertex order, then you'd just have to import the new OBJ and it should update the UVs automatically.
- I know I've tried it just simply importing it but the High details don't get transferred unless I freeze the subdivisions.
It would be worth noting that zbrush flips the UVs so it wont appear exactly the same as you might be expecting, but as long as it doesn't butcher the actual islands themselves then everything should be fine.
- Yeah, I noticed when I did UVMaster,Maya, Zbrush the normals got flipped (red). I could simply leave it with UVMaster, the problem is I have about 30 subtools sharing one uv map. UV Master takes up the whole 0-1 UV space, so I have to resize it in Maya, unless if there is a way to modify the UV Map in Zbrush, which I don't think is possible, is it?
I never get good results when I use project all in Zbrush, which I already tried about a couple dozen times. Something happens to the vertex normals when I export/import, I'm still stumped though on what options are causing it.
I don't think rendering a low poly cage in Maya is very practical. It takes too long to set up the render settings/lighting and doesn't look as good. Since I can get better rendering results in Zbrush. Is there a Mac equivalent program to render out in-game assets?
I meant the UVs themselves get flipped, not the channels.
As for UV Master, If you use the Flatten button you can change the UVs with the move brush, masking, and transpose, and then unflatten.
Rendering a low-poly in Maya is very practical, to display a normal map in the viewport with a couple spotlights and a diffuse map only takes 2-3 minutes.
Like Cryrid said, It looks to me like your uv's are getting broken apart.
I know how to render in Maya, I already know that it takes more set up and more time. There's no way you can get a good enough render in Maya with out severely tweaking the crap out of the render settings and shaders. Shaders are fine in Zbrush. I've done plenty of low poly rendering in Zbrush, it works fine. Like I said the UVs are not broken.
mike @ cryrid.com
Let me know if that link doesn't work
Should be a clean slate, deleted the uvmap, 7 sdiv. It projects fine in UVMaster. Try exporting and modifying the uv's in maya and reimport into zbrush. Zbrush doesn't like the new uvmap created in Maya. It's not the export/import options, I just tried it. Thanks btw.
I think you guys are right....
For some reason when the obj gets imported back into Zbrush. It turns on Groupings. So when I'm copying the new UV information its copying it in sections, like you guys said. I just assumed since I had it off when I exported it would remain off not on. Going to do more tests....
Scale 1.1067
x Offset -0
x Offset 2.3231
z Offset .0382
[ame="
The mesh itself is inverted. It's easier to tell by going to Tools: Display Properties and turning off Double.
So while you're in that subpallete, I'd jump to the highest subidivion level and then hit the flip button to flip the normals. Once that's taken care of, turn off the old texture so it's not so confusing to look at. Give it UVs when it is in this state. From here on out the normal map should bake fine (you might want to turn on adaptive, and turn off SmoothUV).
And if you're happy with the highpoly sculpt, it would probably be faster and better to work with Maya from here on out. The bane of baking in zbrush is that the highpoly has to be a higher subdivision level of the same tool, and if you can't work out an import/export process that keeps things consistent, then you're going to run into quite a few problems even if you just want to change UVs around. By separating the sculpt from your final game mesh you're going to have more freedom over the baking process, and changes you make to the final mesh wont run the risk of altering the sculpt. The bake may take longer, but you'll get more control over it and the tangents should sync up (more importantly you'll also be able to see the result of the normal map on the model, instead of just faking it with a displacement map and matcap-driven specular). Unfortunately I'm not familiar enough with Maya's export options to let you know what needs to be done for a smooth pipeline between the two. With XSI I just keep the default settings + local coordinates, and with zbrush I ignore subgroups. You should maybe check your Preferences:ImportExport settings to make sure it's not automatically trying to flip normals, or import groups.
So export the Highres as an OBJ (it wont need UVs), check that the normals are correctly pointing outwards, and do whatever you need to do to the lowpoly and its UVs in Maya.
I actually did some digging on zbrush central and found out that the normals got inverted when I used the zbrush retoplogy method. I get too many problems using zbrushes retop method so I try to avoid it at all costs. I don't have access to topogun unfortunately otherwise I would use that.
http://www.zbrushcentral.com/showthread.php?166762-Unwelded-UVs
Are you still running into problems? All I had to do with the file was hit the flip button and give it UVs.